Casing for leaf blower

ABSTRACT

Conventional leaf blowers have a supporting frame to where the different components are attached. In order to reduce the noise from the tool and protect some of the components are they provided with covers. This makes the tool heavy and complicated for the operator to use. The claimed invention is a covering casing ( 10 ) that also is the supporting structure for the different components in the tool. The casing reduces the amount of noise spread from the tool and protects the components inside the casing ( 10 ).

[0001] Combustion engine powered leaf blowers are used more and more for different kinds of work. The numbers of areas where leaf blowers are used is increasing and the leaf blowers are replacing traditional brooms. Leaf blowers are an effective and time saving tool for cleaning of large areas like for example parking places, pavements, lawns and footpaths.

[0002] Leaf blowers makes it possible to clean large areas in an easy way. During cleaning of areas with conventional equipment will parked cars on a parking place make it necessary to parts of the area uncleaned. If the same area is cleaned with a leaf blower is it possible to blow away the rubbish underneath the parked cars, which will increase the efficiency, save time and improve the result.

[0003] Even though the leaf blower is an effective tool that helps the operator to clean large areas will the operator work long shifts carrying the leaf blower on the back. Leaf blowers available on the market today are large and heavy with the centre of gravity for the tool placed at a long distance from the back of the operator. This will expose the operator for high loads when the leaf blower is carried on the back of the operator. This type of tools is also generating a lot of noise, which will make it very tiring for the operator as well as for other persons located close to the tool.

[0004] A leaf blower comprises at least a fan with a fan wheel, an engine and a couple of other details that is necessary to make the leaf blower work properly. The leaf blowers that are designed to be carried on the operators back that are available on the market today is designed with the fan and the fan wheel closes to the operators back and secured to a supporting frame for example made of pipes or shaped like a plate. The straps for carrying the leaf blower are secured in the supporting frame. Air to the fan is sucked into an inlet placed on the side of the fan that is turned towards the back of the operator. It must therefore be a gap of about 5 to 10 centimeters between the back of the operator and the inlet to the fan to guarantee that enough air will reach the inlet. The engine is then placed on the fan wheel axle on the side of the fan wheel that is turned away from the back of the operator.

[0005] A leaf blower designed like this will have the centre of gravity placed a long distance for the back of the operator. The distance between the centre of gravity for the tool and the back of the operator is very important since it is related to the loads that the operator is exposed to as well as how easy it is to handle the tool. This distance should be as short as possible in order to minimise the loads on the operator.

[0006] There are a couple of different leaf blowers available on the market but all of them have some sort of supporting fame. To this supporting frame, often made of pipes or plates, are the different components in the leaf blower attached. Some of these components may be provided by covers that protects the component or for reducing the noise that is spread from the component. These known solutions have the drawbacks that they are heavy, takes a lot of space and are not considered as effective for lowering the noise level around the tools. This type of leaf blowers is illustrated in U.S. Pat. No. 5,195,208.

[0007] The known models of leaf blowers have several drawbacks. The design of leaf blowers must therefore be improved so that the loads on the operators and the amount of noise that are spread from the tool are reduced. The claimed invention reduces both the loads on the operator as well as the noise spread from the tool.

[0008] The claimed invention solves the problems described above by using a casing that covers all components in the leaf blower's machinery. The casing is an effective insulation that reduces the noise that is spread from the tool. The casing comprises to sections, one bottom section and a lid. In the claimed leaf blower is the supporting frame of pipes or plates replaced by the casing that is the supporting structure that the components are attached to instead of a supporting frame. This solution reduces the weight of the tool.

[0009] The casing is made of a material that is good for noise insulation, which reduces the amount of noise in the environment of the tool considerably.

[0010] The casing is also working as a protecting shell that surrounds all the components during careless treatment of the tool so that the tool will last longer. The casing must consequently be made of a material that can resist bumps and wear, is effective for sound insulation and also possible to form in the desired shape. The casing is therefor preferably made in a plastic material and provided with fastening means that secures the two sections of the casing together in a reliably way. The outside of the casing is smooth and plain in order to prevent the leaf blower from connecting to other tings during use and transportation. The smooth and plain outside of the casing also reduces the risk that the operator will connect to something when the leaf blower is carried on the back of the operator. All components related to the machinery of the leaf blower are secured to the bottom section of the casing as well as the straps that makes it possible for the operator to carry the leaf blower. The bottom section is shaped in order to be as comfortable as possible for the operator to carry on the back.

[0011] The casing is shaped almost like a rucksack and has an handle on the top of the casing to facilitate the carrying, storing and transportation of the leaf blower when it is not placed on the back of the operator.

[0012] The casing must have a few openings to make the tool work properly. There is one air inlet for the air to the fan and the engine and one opening where the pipe from the fan outlet pass through the casing. The air inlet is placed in the lower part of the casing in order to minimise the possibility for the sound waves inside the casing to pass out from the casing through the air inlet. In the lower part of the casing is also the gasoline tank placed so that the tank will help generating a sound wave trap in the air inlet.

[0013] The exhaust gases from the engine can be lead out from the casing via the pipe from the fan outlet or another separate opening in the casing. This opening is then placed on the side of the casing facing away from the back of the operator close to the muffler in order to minimise the distance between the muffler and the opening. This opening is also provided with a sound wave trap so that the sound waves are prevented from leaving the casing. The opening for the pipe from the fan outlet is placed so that the pipe leaves the either of the sides of the casing in a direction that makes the use of the tool comfortable for the operator. This means that the pipe will leave the casing on one of the sides and pointing downwards to the hands of the operator. Also this opening is designed to stop as much noise as possible from leaving the casing and the connection between the pipe and the softer pipe that the operator are using for the cleaning is an effective damper of the noise generated from the engine and the fan. The casing can also be provided with an opening for ventilation of heated air from the inside of the casing. This opening is preferably placed in the top of the casing since the heated air will raise upwards because of convection.

[0014] To further reduce the risk for transferring noise and vibrations from the components inside the casing to the operator and the environment are the components attached to the casing via insulators for vibrations and sound. This improves the working conditions for the operator.

[0015] One embodiment of the claimed invention is illustrated in FIGS. 1-5.

[0016]FIG. 1. Shows a side view of the casing.

[0017]FIG. 2. Shows the side of the casing that is turned backwards from the operator.

[0018]FIG. 3. Shows the casing seen from above.

[0019]FIG. 4. Shows the side of the casing that is turned towards the back of the operator.

[0020]FIG. 5. Shows a perspective view of the section of the casing that is closes to the back of the operator during normal use of the leaf blower.

[0021]FIG. 1 illustrates a casing 10 that is shaped almost like a middle size rucksack and covers the different components in the leaf blower's machinery. The casing 10 comprises two sections, one bottom section 11 and a lid 12. The two sections are secured to each other by fastening means 13 placed around the sides of the casing 10.

[0022]FIG. 2 illustrates the side of the casing 10 that is turned away from the back of the operator when the leaf blower is in its right position on the back of the operator. In order to facilitate transportation and lifting of the leaf blower is the casing provided with a handle 14 in the top of the casing 10. Exhaust gases from the engine pass through the casing in an opening 15 in the lid 12 that also includes a ventilation opening 23 for heated air from the inside of the casing 10. The casing 10 also includes a passage 16 where the not illustrated pipe from the fan inside the casing 10 is lead through the casing 10. The passage 16 is placed so that the operator will have a comfortable working position for the arm. On the opposite side of the passage 16 is a starting rope and a starting handle 22 for the engine inside the casing 10 placed. The position of the starting handle 22 is chosen so that he operator will reach the starting handle 22 when the leaf blower is in the position on the back of the operator.

[0023] The leaf blower is during normal use carried on the back of the operator. FIG. 3 illustrates the shape of bottom section 11 that is designed so that it is comfortable for the operator to carry on the back.

[0024] On the side of the casing that is turned towards the back of the operator are straps of the same type as the one used for rucksacks attached to the casing, they are not illustrated in the figures. The bottom section 11 of the casing 10 is provided with two reinforced sections 17 to where the straps are attached. The straps are in one end attached to the first reinforced section 17 and the other end to a second reinforced section 18. In order to reduce the loads on the back of the operator further can the leaf blower be provided with a belt that also is attached to the second reinforced sections 18.

[0025] The bottom section 11 of the casing 10 is the supporting structure for the tool. The components are attached to the bottom section 11. The inside of the bottom section 11 is therefore provided with several fastening means 19 a, 19 b, 19 c, to where the components are attached. In the lower part of the casing 10 is an air inlet 20 and a tank 21 for gasoline placed. This solution with the air inlet 20 and the tank 21 placed outside the air inlet creates an effective sound wave trap that that reduces the amount of sound waves that leaves the casing through the air inlet 20. 

1. Casing (10) for a combustion engine powered tool that is carried on the back of the operator, characterised in that the casing (10) covers all the noise generating components in the tool and is the supporting structure for the components in the tool.
 2. Casing (10) according to claim 1, characterised in that the casing (10) comprises two sections, a bottom section (11) and a lid (12).
 3. Casing (10) according to claim 2, characterised in that the bottom section (11) is the supporting structure for the components inside the casing (10).
 4. Casing (10) according to claim 2 or 3, characterised in that straps and/or a belt for carrying of the tool are attached to the bottom section (11).
 5. Casing (10) according to any of the previous claims, characterised in that the casing (10) is made of a sound insulating and/or a bump and wear resistant material.
 6. Casing (10) according to any of the previous claims, characterised in that the casing (10) has a handle (14) integrated in the top of the casing (10).
 7. Casing (10) according to any of the previous claims, characterised in that the tool has a starting rope and a starting handle (22) placed on one of the sides of the casing
 8. Casing (10) according to any of the previous claims, characterised in that the casing (10) has an air inlet (20) in the lower part of the casing (10).
 9. Casing (10) according to claim 8, characterised in that the casing (10) has a tank (21) for gasoline in the lower part of the casing (10) placed outside the air inlet (20). 